Robert gottschalk

ABSTRACT

A SEAL COMPRISES TWO CONCENTRIC PISTON RINGS HAVING CONTACTING COMPLEMENTARY CONICAL SURFACES. THE PISTON RINGS ARE AXIALLY SPRING BIASED. THE OUTER PISTON RING IS SPLIT. AN AXIAL SPRING FORCE IS TRANSLATED INTO AXIAL AND RADIAL COMPONENTS, THE RADIAL COMPONENT RESULTING FROM THE RELATIVE MOVEMENT BETWEEN THE ADJACENT CONICAL SURFACES. THE SEAL IS EFFECTIVE AT ZERO SPEEDS AND HAS INCREASED EFFECTIVENESS DUE TO CENTRIFUGAL FORCE AT OPERATING SPEEDS.

Oct. 12, 1971 w, pusT K Re. 27,18

SLIPPING CONE 5E Original Filed larch 4., 1968 BY M W ATT NEYS UnitedStates Patent olfice Re. 27,188 Reissued Oct. 12, 1971 27,188 SLIPPINGCONE SEAL Werner Pnstelnik, Laudong, Austria, assignor to AvcoCorporation, Stratford, Conn.

Original No. 3,502,343, dated Mar. 24, 1970, Ser. No. 710,305, Mar. 4,1968. Application for reissue June 25, 1970, Ser. No. 49,676

Int. Cl. F16j 15/16; F161: 41/00 U.S. Cl. 277-25 Claims Matter enclosedin heavy brackets appears in the original patent but forms no part ofthis reissue specification; matter printed in italics indicates theadditions made by reissue.

ABSTRACT OF THE DISCLOSURE A seal comprises two concentric piston ringshaving contacting complementary conical surfaces. The piston rings areaxially spring biased. The outer piston ring is split. An axial springforce is translated into axial and radial components, the radialcomponent resulting from the relative movement between the adjacentconical surfaces. The seal is effective at zero speeds and has increasedeffectiveness due to centrifugal force at operating speeds.

SUMMARY OF THE INVENTION This invention provides a seal which iseffective at zero speeds as well as at high speeds. At Zero or lowspeeds an axially applied spring force urges two contactingcomplementary conical piston-type rings axially against a r0- tatingshoulder and radially against a stationary housing. The outer ring issplit and expands due to centrifugal forces as the speed of the rotor isincreased. The expansion of the piston type ring permits the applicationof additional spring pressure to maintain the axial and radial sealcontact pressures relatively constant. The inventive concept resides inthe use of the contacting complementary concentric piston-type sealingrings, the outer one of which is split and both of which are axiallyloaded by a spring.

THE DRAWINGS FIG. 1 is a cross section of a seal utilizing the invention; and

FIG. 2 is a view showing the split outer ring.

DESCRIPTION The disclosed seal is contained within a stationary housingprovided with a conventional O-ring 12 for mounting in the casing of amachine such as a motor or an engine. A rotor 14 may be a separatesealing element which is mountable on a shaft or the rotor 14 may be theshaft of such a machine. Sealing between the rotor 14 and the stationaryhousing 10 is provided by means of two concentric seal rings 18 and 20.The seal rings 18 and 20 are provided with relatively movablecomplementary conical contacting surfaces 22 and 24, respectively. Theouter ring 18 is split, as shown in FIG. 2, but is provided in aconventional manner with overlapping abutting portions 26 and 28. Therings 18 and 20 are preloaded by means of springs 30 positioned withinretainers 32. The springs and retainers are angularly locked in positionby means of pins 33 extending into a lock nut 34. The lock nut 34axially positions the springs. The retainer 32 is urged against the ring18 which moves axially and radially with respect to the ring 20, thiscombined movement being due to the complementary conical surfaces 22 and24. The axial movement forces the ring 20 against the sealing surface ofshoulder 36 of the rotor 14 while the radial movement forces the outerperiphery of the ring 18 against the inner periphery of the stationaryhousing 10.

A snap ring 38 positioned in the stationary housing 10 prevents thepreloaded elements from being forced out of the housing when the rotoris not positioned therein.

In effect the seal operates like a spinning piston ring. At zero rpm.the preloaded retainer 32 bears against the conical rings 18 and 20toprovide both radial and axial sealing. As the speed of the rotor 14increases,the radial sealing efiect is increased by centrifugal force.This results from the expansion of the ring 18, the portions 26 and 28of which are relatively movable. As the ring 18 expands, it movesradially against the stationary housing 10, but the springs 30 causefurther axial movement against the ring 20 so as to maintain thepreloading between the seal 20 and the surface 36 of the rotor 14.

The minimum theoretical angle of the conical surfaces is 22 /2 degrees.In practical applications this angle could be larger to prevent therings from seizing. When rotating, the two carbon rings 18 and 20 willrotate with different speeds but will always be in balance as a functionof the centrifugal forces transmitted between the rings 18 and 20 andthe force of the springs 30. Depending on thermal and speed growth,there will always be a self-adjustment of the two rings 18 and 20against the springs 30.

It will be apparent to persons skilled in the art that this invention issubject to various modifications and adapta tions. It is intendedtherefore that the scope of the invention be limited only by theappended claims as interpreted in the light of the prior art.

I claim:

1. A seal comprising:

an annular stationary housing;

a rotor concentrically positioned within said housing,

said rotor having a shoulder;

an inner and an outer seal ring concentrically positioned in the spacedefined by said housing, said rotor and said shoulder, said rings havingcontacting complementary conical surfaces; and

[a plurality of springs] means axially preloading said rings, said[springs] means axially urging the conical surface of said outer ringagainst the conical surface of said inner ring, whereby said outer ringis radially preloaded against said stationary housing and said innerring is axially preloaded against said shoulder.

2. The invention as defined in claim 1 wherein a snap ring is providedfor maintaining said seal rings within the housing when said rotor isnot in position within said housing.

3. The invention as defined in claim 2 wherein said means axiallyprelaading said rings comprises a plurality of springs and wherein oneend of each said spring is contained within a retainer, each of saidretainers being slidable on said outer ring, the other end of saidspring being fixed to said housing.

4. The invention as defined in claim 3 wherein said other end of saidspring is fixed to said housing by means of a lock nut internallythreaded into said housing, said lock nut having an annular groove forreceiving the other end of said springs.

5. The invention as defined in claim 1 wherein the outer seal ring issplit.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS 1,120,181 12/1914 Clement 27781 2,372,103 3/1945Morton 277--25 2,889,159 6/1959 Jensen 27740 3,165,323 6/1965 Hamano2774l 3,250,539 5/1966 Kurz et al 277-41 SAMUEL B. ROTHBERG, PrimaryExaminer UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentRFZ 27189 Dated October 12 1971 Inventor-( Martin Hutterer It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 5, line 8 change "self-loading" to selfunloading- Column 6, line8 change "inert" to invert--.

Signed and sealed this lLtth day of March 1972.

(SEAL) Attest:

EDWARD M.FLETCEER,JR. ROBERT GOTTSCHALK Attesting Officer 7 Commissionerof Patents RRS:in 10/26/71 FORM PC4050 USCOMM-DC seam-ps9 a LL54GOVERNMENT PRINYING OFFICE T 959 O356 JJ4

